druid/docs/content/ingestion/delete-data.md

layout	title
doc_page	Deleting Data

Deleting Data

Permanent deletion of a Druid segment has two steps:

1. The segment must first be marked as "unused". This occurs when a segment is dropped by retention rules, and when a user manually disables a segment through the Coordinator API.
2. After segments have been marked as "unused", a Kill Task will delete any "unused" segments from Druid's metadata store as well as deep storage.

For documentation on retention rules, please see Data Retention.

For documentation on disabling segments using the Coordinator API, please see Coordinator Delete API

A data deletion tutorial is available at Tutorial: Deleting data

Kill Task

Kill tasks delete all information about a segment and removes it from deep storage. Killable segments must be disabled (used==0) in the Druid segment table. The available grammar is:

{
    "type": "kill",
    "id": <task_id>,
    "dataSource": <task_datasource>,
    "interval" : <all_segments_in_this_interval_will_die!>,
    "context": <task context>
}